[grinder_gary]

I previously built a Precision plasma table and have had it make money for the last 5 years.

We have the materials and another gantry coming for a new table but this one for a router. The work area will be 48x96 with room for oversize table top.

My question is what do you use for a table top? With plasma, you have a water pan that holds your slats and your material sits on top of the slats.

With a router, I need a table top, then be able to put a good spoil board on to that.I was wondering what you all use when you built your tables?

Any help is appreciated!

Thanks in advance,

Grindergary

[wizard]

Since you are already running a plasma machine the first question that comes to mind is this; will you be machining any sorts of metal on the machine. If you primary interest is wood then MDF is passable. If you expect to do metal then a metal table is in order. The reason being any serious metal cutting will require a lube/coolant, this is a bad combo with wood products.


Note that on machines this size you need a frame under the table or part of the table. You don't want to leave this supporting framework as an after thought.

[grinder_gary]

No this table is strictly wood products. I understand what you mean by needing a frame under the table for support of the sheets. I just am trying to figure out what way to do it. Can't seem to find any pictures of a system that is being used. I will keep looking at build threads and maybe get an idea.

Thanks for your response!

Gary

[Devastator]

Large torsion box?

[LeeWay]

I take it that humidity may not be too bad in your area. You could use MDF.
I would probably prefer plywood as the sub base. Then you can cut up some 3/4" MDF and use 1/2" T-tracks in between. Pick your own spacing and frequency. That way you can level out that section of MDF many times and use it for a spoil board. You can replace parts of it that gets damaged and relevel. With T-track, you can use T-nuts or toe clamps. Unlimited varieties actually.
The torsion box is a fine suggestion too. It doesn't have to be very thick to make it solid.

[FandZ]

I've always built my cnc machines as table top machines from 18x18 inch machines to 6x10.5 foot machine. When you go over a 4 foot wide machine it can get a little tricky because sheet goods you use for your base only goes up to 4 foot wide. At that point using multiple aluminum extrusions between your X rails and having a 4 foot wide table underneath makes since. On top of the cross beams between your X axis, I like to use two sheets of MDF that have been glued together then 1 sheet on top that I screw down as a spoil board. One thing I would highly recommend is not building a base under your large cnc machine that won't let you add a vacuum hold down system later on.

[ger21]

Plywood is a little better choice than MDF for the table base layer, as it's a little more stable than MDF. A lot of people use a layer of plywood, then a layer of MDF, followed by another layer of MDF for the spoilboard.

[grinder_gary]

Large torsion box?

Don't mean to sound dumb, but what is a torsion box?

Gary

[grinder_gary]

Seeing as I have not started to build the base of the frame yet, I understand what you mean. We, my partner and I, are discussing how high the top should be so we can machine certain sizes of material. If I build a base with extrusion, say 1 1/2" high and then 3/4" then 1 1/2" for 2 sheets plus another for the spoil board.I need to lower the support for the sheet supports to get our working hight. That is why we are trying to figure out what to use. Thank you for your response, informative.

Gary

I've always built my cnc machines as table top machines from 18x18 inch machines to 6x10.5 foot machine. When you go over a 4 foot wide machine it can get a little tricky because sheet goods you use for your base only goes up to 4 foot wide. At that point using multiple aluminum extrusions between your X rails and having a 4 foot wide table underneath makes since. On top of the cross beams between your X axis, I like to use two sheets of MDF that have been glued together then 1 sheet on top that I screw down as a spoil board. One thing I would highly recommend is not building a base under your large cnc machine that won't let you add a vacuum hold down system later on.

[Devastator]

Don't mean to sound dumb, but what is a torsion box?

Gary

https://www.google.com/search?q=tors...FZCViAodyuoGwg

[grinder_gary]

Thanks, Now i remember that from years ago reading on this forum.

Wife calls it oldtimers, lol

Thanks

Gary